Hydrogenating asphaltic mixtures



United States Patent O s 190 831 ,HYDROGENATING: ASPHALTIC MHXTURES Earl M. Honeycutt, West Chester, Pa., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey No Drawing. Filed Feb. 5, 1963, Ser. No. 256,265

8 Claims. (Cl. 208-464) carbon components. Depending on the severity of the conditions, differing extents of decomposition to form lower-boiling products such as gasoline, gas oil, etc. are obtained'in the process.

Hydrogen produced in processes for the reforming of hydrocarbons has been proposed for use in hydrorefining and hydrocracking processes. But it has not been appreciated that this hydrogen could satisfactorily be used in the hydrogenation of asphaltic charge stocks without separating the hydrogen from the reformed hydrocarbons beforehand.

The present invention involves hydrogenating asphaltic hydrocarbon mixtures by contact with a mixture of reformed hydrocarbons and hydrogen produced in a reforming process. This procedure eliminates the need for separating reformed hydrocarbons from hydrogen prior to the hydrogenation. The separation of hydrogen from both reformed hydrocarbons and hydrocarbon products of the hydrogenation is done after the hydrogenation. The separation of the reformed products into desired fractions and of the hydrogenated products into desired fractions is also done after the hydrogenation, usually With a saving in cost as compared with separately fractionating the reformed products and the hydrogenated products. The process according to the invention greatly reduces, as compared with separate reforming and hydrogenation plants, the capital and operating costs of an asphaltic hydrocarbon hydrogenation plant, over and above the costs of the reforming plant with which it is associated.

It was not known before now that reformed hydrocarbons could be used in hydrogenation of asphaltic hydrocarbons without the often undesirable result of hydrogenating too much of the aromatics in the 'reformate. This result is avoided in the process of the invention, since the asphaltic components of the hydrogenation feed inhibit hydrogenation of the aromatics. Some increase in hydrogen-to-carbon ratio of the hydrogenation feed usual- 1y takesplace, but the increase in hydrogen-to-carbon ratio of the reformate during the hydrogenation is less than would be obtained in the absence of the asphaltic components, and is small enough to be outweighed, as a disadvantage, by the advantages resulting from the pres ence of the reformate during the hydrogenation.

The gas oil product obtained in the hydrogenation, or suitable fractions thereof, is a good charge stock for a conventional catalytic cracking process, and is generally superior for thatpurpose to the corresponding portion of the residual charge stock to the hydrogenation. The residual product is also a better cracking stock than the corresponding portion of the charge, and is also a better residual fuel because of its lower viscosity and sulfur content.

The process according to the invention produces, as one result, high octane gasoline from low octane fractions by reforming. Additional gasoline may also be produced in the process, either by direct conversion of constituents of the residue to gasoline in the hydrogenation, or by crack ing of heavier constituents of the hydrogenated product in a separate conventional catalytic cracking process, or both. Improvedresidual fuel may also be produced in the process byreducing the viscosity and sulfur content of the residue as a result of the hydrogenation.

Reaction conditions for use according to the invention include in the reforming stage temperatures of 750 to 1000 F., pressures of 250 @750 p.s.i.g., and liquid hourly space velocities of 0.5 to 5 volumes'of hydrocarbon per volume of catalyst bed per hour, and in the hydrogenation stage temperatures of 650 to 950 F., pressures of 250 to 1000 p.s.i.g., space velocities of 0.5 to 5 based on reformate plus asphaltic charge, and hydrogen ratios in the range from 1,000 to 15,000 standard cubic feet per barrel of charge in the hydrogenation. Preferably, the temperature in the hydrogenation is at least 725 F. and more preferably at least 775 F. Preferably, the pressure in the hydrogenation is at least 500 p.s.i.g. However, other known conditions for reforming and for hydrogenation of asphaltie hydrocarbons can be employed.

Suitable reforming catalysts include platinum on an alumina or silica-alumina support, WllZlIOI' without combined halogen, molybdena on alumina, chromia-alumina' and other known reforming catalysts. Suitable hydrogenation catalysts include cobalt, nickel, molybdenum, tungsten etc. and compounds thereof, e;g. cobalt-molybdenum oxide catalysts, tungsten-nickel sulfide catalysts; nickel on silica-alumina catalysts; suitable carriers include activated clay, alumina, etc. The catalysts disclosed for reforming and for hydrogenation respectively in K. A. Kobe et al., Advances in Petroleum Chemistry and Refining, volume IV, pages 297 to 314 (1961), and the references cited therein, are suitable for use according to the invention. Preferably a platinum catalyst is used in the reforming, and a molybdenum-, tungsten, or cobaltand molybdenum-containing catalyst in the hydrogenation.

Preferably, the pressure in the hydrogenation stage does not exceed the pressure in the reforming stage, since it is usually undesirable from an economic standpoint to raise the pressure between the stages. However, raising of the pressure, e.g. to 2000 psig or higher, may be practical in some cases, and is therefore within the scope of the invention. The pressures in the respective stages are preferably within the previously stated limits, since higher pressures may result in excessive hydrogenation of aromatics in the gasoline boiling range, andlower pres- Patented June 22,1955

be used. Preferably, but not necessarily, the asphaltene content of the charge stock is in the range from to 25 weight percent.

The reforming process which precedes the hydrogenation can be any process which involves dehydrogenation of naphthenes to aromatics, and any known process which involves such reaction can be employed. Other reactions commonly involved in known reforming processes, e.g. isomerization, dehydrocyclization, cracking, etc., can also be involved, but are not essential to the operation according to the invention. The charge stock for the reforming process can be any hydrocarbon mixture containing naphthenes or other hydrocarbons convertible to aromatic hydrocarbons by reforming processes. Preferably, the charge boils within the range from 150 F. to 600 F., but this is not essential in all cases. Straight run or cracked petroleum fractions can be employed, as well as suitable non-petroleum hydrocarbon charge stocks.

Preferably, the reformate is introduced from the reforming zone into the hydrogenation zone with only such adjustment of temperature as is needed to provided the desired conditions in the hydrogenation. Usually the temperature in the hydrogenation will be at least 50 F. lower than that in reforming. The asphaltic hydrocarbon may be admixed with the reformate and hydrogen prior to introduction into the hydrogenation zone, or alternatively may be introduced separately into that zone.

The following examples illustrate the invention:

Example I Petroleum naphtha is catalytically reformed, the product mixture of reformate and hydrogen is admixed with asphaltic petroleum residue, and the resulting mixture is subjected to elevated temperature and pressure to effect hydrogenation of nonhydrocarbons and coke-forming constituents of the desidue. The following table shows the process conditions and results.

IBP 400 660 20% 790 30% 865 40% 927 50% 1010 60% 1048 Diluent and hydrogen: Mixture of reformate and hydrogen, introduced without presure change from reforming stage, volume ratio reformate to residue 2: 1.

Temperature: 820 F.

' Space Rate: One volume of residue per volume of catalyst bed per hour.

Catalyst: Cobalt and molybdenum oxides on alumina.

Typical approximate product distribution, disregarding about 0.5% dry gas (C to C Vol. percent Gasoline (C to 400 F.) 75 Gas oil (400 to 1000 F.) 20 Residue (boiling above 1000 F.) 5

The gasoline product includes hydrocarbons derived from the reformate, as well as hydrocarbons produced by cracking of components of the residue. The reformate portion of the gasoline product has aromatic content only slightly reduced from that of the corresponding fraction of the reformate prior to the hydrogenation. Much greater reduction in aromatic content is obtained when the reformate is subjected to the same hydrogenation conditions in the absence of a heavier hydrocarbon material, or in the presence of a heavier hydrocarbon material such as gas oil which does not contain asphaltic material.

The presence of the reformate during the hydrogenation provides more uniform temperatures, in the catalyst bed through which the residue is percolated in the hydrogenation step, then those which are obtained in the same operation in the absence of the reformate.

Example II In a preferred but not essential embodiment, the reformate, hydrogen and residue are contacted at a lower temperature, e.g. 700 F., prior to the hydrogenation stage described in Example I. This pre-contacting hydrogenates potential coke-formers and cuts down the coke formation in the later hydrogenation at higher temperature. Typical conditions for the pre-contacting are the following.

Diluent: volume ratio reformate to residue 1:1.

Temperature: 700 F.

Space rate: 4 volumes of residue per volume of catalyst bed per hour.

Hydrogen-to-charge ratio: 12,000 standard cubic feet per barrel.

In this embodiment, half of the available mixture of reformate and hydrogen is admixed with the residue prior to the 700 F. hydrogenation, and the remaining half of the available mixture is admixed with the product of the 700 F. hydrogenation prior to introduction into the higher temperature hydrogenation.

Example III In another run, the same procedure is employed as in Example I, except that a different residue is hydrogenated, and different temperature and space rate are employed in the hydrogenation.

Charge: 10% residue from Gulf Coastal crude, API gravity 11.4, sulfur content 1.3%, Ramsbottom carbon content 13.6%.

Temperature: 800 F.

Space rate: One volume of residue per volume of catalyst bed per hour.

The following approximate product distribution is typically obtained, disregarding dry gas:

Percent Gasoline C 400 F. 70 Gas oil 400-1000 F. 10 Residue 20 The milder conditions as compared with the run at 820 F. result in a lower extent of conversion of heavy material to gasoline and gas oil, while obtaining good reduction of sulfur and Ramsbottom carbon and results otherwise similar to those obtained in the higher temperature run.

I claim:

1. Process for making high octane gasoline and for making improved products from asphaltic mixtures which comprises catalytically reforming hydrocarbons to produce reformate and hydrogen, and contacting substantially all of said reformate and said hydrogen without intermediate separation, with an asphaltic hydrocarbon mixture under hydrogenation conditions at a temperature in the range from 775 to 950 F. in the presence of a metallic hydrogenation catalyst, whereby said mixture is hydrogenated in the presence of said reformate as diluent to reduce the Ramsbottom carbon content of said mixture, and whereby the asphaltic material in said mixture inhibits hydrogenation of aromatics in said reformate 2. Process according to claim 1 wherein the reforming temperature is 750 to 1000 F.

3. Process according to claim 1 wherein said hydrocarbons are a petroleum naphtha fraction.

4. Process according to claim 1 wherein said asphaltic hydrocarbon mixture is a petroleum residue.

5. Process according to claim 1 wherein said asphaltic hydrocarbon mixture is a straight run petroleum residue.

6. Process according to claim 1 wherein a platinum catalyst is employed in said reforming, and a catalyst containing a metal selected from the group consisting of molybdenum and tungsten is employed in said hydrogenation.

7. Process according to claim 1 wherein said reforming and said hydrogenation are performed in separate zones with separate reforming and hydrogenation catalysts respectively.

8. Process according to claim 6 wherein the hydrogenation pressure is in the range from 250 to 1000 psig. respectively.

References Cited by the Examiner UNITED STATES PATENTS 2,333,625 11/43 Angell 20856 2,339,108 1/44 Pier et al. 20844 2,345,877 4/44 Kroenig 20844 2,532,615 12/50 Ewell 20862 2,703,308 3/55 Oblad et a1 208-110 2,758,059 8/56 Berg 208--97 2,768,936 10/56 Anderson et al 208112 2,772,215 11/56 Hemminger 208-56 2,772,222 11/ 56 Stewart et a1 20856 2,983,669 5/61 Noll 208-97 FOREIGN PATENTS 313,433 12/ 29 Great Britain.

20 ALPHONSO D. SULLIVAN, Primary Examiner. 

1. PROCESS FOR MAKING HIGH OCTANE GASOLINE AND FOR MAKING IMPROVED PRODUCTS FROM ASPHALTIC MIXTURES WHICH COMPRISE CATALYTICALLY REFORMING HYDROCARBONS TO PRODUCE REFORMATE AND HYDROGEN, AND CONTACTING SUBSTANTIALLY ALL OF SAID REFORMATE AND SAID HYDROGEN WITHOUT INTERMEDIATE SEPARATION, WITH AN ASPHALTIC HYDROCARBON MIXTURE UNDER HYDROGENATION CONDITIONS AT A TEMPERATURE IN THE RANGE FROM 775 TO 950*F. IN THE PRESENCE OF A METALLIC HYDROGENATION CATALYST, WHEREBY SAID MIXTURE IS HYDROGENATED IN THE PRESENCE OF SAID REFORMATE AS DILUENT TO REDUCE THE RAMSOBOTTOM CARBON CONTENT OF SAID MIXTURE, AND WHEREBY THE ASPHALTIC MATERIAL IN SAID MIXTURE INHIBITS HYDROGENATION OF AROMATICS IN SAID REFORMATE THAT WOULD OTHERWISE OCCUR THROUGH CONTACT OF SAID REFORMATE WITH SAID CATALYST. 